0.15-MU-M BURIED-CHANNEL P-MOSFETS WITH ULTRATHIN BORON-DOPED EPITAXIAL SI LAYER

We demonstrated silicon MOSFET's with a counter-doped ultrathin epitax ial channel grown by low-temperature UHV-CVD; this allows the channel region to be doped with boron with high precision. The boron concentra tion and epitaxial layer thickness can be chosen independently, and so it is easy to adjust the threshold voltage of the buried-channel p-MO SFET's with n-type polysilicon gates. It was confirmed that choosing a n ultrathin epitaxial layer at 10 nm leads to suppression of the short -channel effects in buried-channel p-MOSFET's with gate length down to 0.15 mu m, while maintaining an appropriate value of threshold voltag e.